Blake Lively says there is no secret to her great physique. She doesn't diet or workout, she isn't careful about her portions or how her food is prepared. Lively said she has just one secret to looking great -- her age.

"Being 25 years old. That and a good metabolism," Lively tells the October 2012 issue of Marie Claire. "I could lie and put it down to dog walking, but you would be well within your rights to call my bluff: my dog weights three pounds. I take six steps and she's done for."

The actress, who just married Ryan Reynolds over the weekend, admits she will need a much stricter diet when she is older. However, for the time being, Lively spends a lot of time in her kitchen, cooking and baking.

"To be around me, you have to love food or I'm the most obnoxious person you've ever met. I'm in a big cooking phase," she said. "That's all I talk about. If you went to my house and didn't know who it belonged to, you would not think it belonged to an actress. There's no memorabilia from my career, no showbizzy pictures on the wall. You would think it was the house of a cooking obsessive. I even have a special area set aside just for baking cupcakes."